The present invention relates to an igniter for an internal combustion engine, and especially relates to a cylindrical igniter installed in a plug hole provided in a cylinder head compartment of said internal combustion engine.
As a conventional igniter for the internal combustion engine, it is known to provide a unified ignition coil and power switch. The power switch switches on and off a first electric current of an ignition coil. The igniter is installed in a plug hole provided in the cylinder head compartment of the internal combustion engine.
For example, the igniter described in the Utility Model Laid-open 4-62359 (1992) reference has a cylindrical shape. A center core thereof (open magnetic circuit iron core) is arranged in a central part of the cylindrical shape. A primary coil and a secondary coil are wound around the circumference of the center core. The igniter is constructed with an ignition coil body in which a side core (outer packing iron core) around the circumference of the secondary coil and an igniter unit (integrated circuit package body) are arranged in order to accommodate a power switch on the upper part of the ignition coil body, thereby the ignition coil body and the igniter unit are mounted in one under the outer packing case forming a coil accommodating compartment of the cylindrical shape. A connector compartment for electrical connections is disposed on an upper part of the outer packing case.
In the above-mentioned prior art, when the coil body is received in the plug hole, the igniter unit extends out into the upper part of the plug hole and the connector compartment is arranged in the upper part of the igniter unit, thereby an inconvenience arises in that the total height of the ignition device becomes too high.